An ever-increasing quantity of media content is being produced that can be consumed (e.g. viewed) by a content consuming user (content consumer) on a media (e.g. viewing) device, such as a television (“TV”) or similar. Increasingly, television viewers are using “companion user devices” (such as smartphones, tablets etc.) to supplement their enjoyment of TV-based content. A companion user device is equivalently referred to herein as “companion device” and “user device”. The user may be finding more information about a show or movie; they may be commenting about it on social media or they might be looking for other things to watch next.
These interactions are increasingly being joined by other types of engagement which seek to involve the viewer more closely with the content. Examples of this include the companion device offering: polls and votes to rate or respond to events as they happen; quiz questions to allow viewers to play along or contribute to a live event; access to richer content about the main thread such as behind the scenes clips, replays, alternative angles etc.
Existing ACR (“Automatic Content Recognition”) techniques go some way towards synchronizing companion device behaviour with the delivery of the primary media content by the media device. For instance, existing “audio watermark” techniques can be used to provide synchronization signals for use by the companion device. Such known watermarking techniques rely on encoding information into audio of the media content in a way that is inaudible to a human ear but which can be decoded from the audio when received via a microphone of the companion device.
One such watermarking technique involves encoding information in the media content audio at a particular (temporal) point which conveys an expected action intended to be performed by the companion device at that point. For instance, where the media content is of a sporting event, the point may be a point at which a goal is scored and the information may be a “goal event” identifier, intended to trigger a goal-related companion device action at that point.
Another such watermarking technique involves encoding reference time instants at various respective reference points in the media content as watermarks. The played-out watermark constitutes a synchronization signal or “heartbeat” that is received by a companion device. The companion device may access stored associations of the reference time instants with expected actions intended to be performed by the companion device. When a synchronization signal encoding a reference time instant is received, an expected action associated with that reference time instant may be triggered in response.